共查询到20条相似文献,搜索用时 10 毫秒
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固相反应法制备了Sr1-xCaxRuO3系列,X射线衍射确定样品的相结构为正交畸变钙钛矿结构.随Ca替代量x的增加,晶格常数a基本保持不变,而b和c随之减小,晶格畸变更加明显.物理性质测量系统(PPMS)测量了样品的交流磁化率,零场冷却和加场冷却磁化强度.Curie-Weiss定律确定了样品的顺磁Curie温度Tp.结果表明,随x的增加,Tp减小.当x<0.6时Tp大于零;当x>0.6时Tp小于零.利用交流磁化率随温度变化的关系确定样品的铁磁Curie温度Tc,随x的增加Tc减小.当x=0.8时,Tc降至4K;而当x=1.0时,即使温度降到1.7K,也未出现磁有序.样品磁性随Ca替代量x的变化是其结构变化的直接结果. 相似文献
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Xu Rengen Wang Xinhua Wu Jianmin Pan Hongge Chen Changpin Wang Qidong Dai Lichi Department of Materials Science Engineering Zhejiang University Hangzhou P. R. China Department Central Iron Steel Research Institute 《中国有色金属学会会刊》1999,9(1)
INTRODUCTIONItiswelknownthatSm2Fe17Nycompoundshavegoodintrinsicmagneticproperties[1].BecauseofthepoorstabilityofSm2Fe17Nyat... 相似文献
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L.L. Liu X.F. Bi S.K. Gong H.B. Xu X. Y. Yuan Department of Materials Science Engineering Beijing University of Aeronautics Astronautics Beijing China 《金属学报(英文版)》2002,15(2):182-186
1. IntroductionAIllltili1},er ll1aterials attract l1lucll l1lore attelltioll[l--3I, because tlley provide a l1ewllletllod to desigll ll1aterials to lueet 1urio[[s requirelllellts. IIl additiol1, tlle developnlelltof electroll bea111 pl1}sical vapor deposi… 相似文献
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ZHANG Lin LIU Yihua Shandong University Jinan China WANG Hao Dongnan University Nanjing China engineer Department of Physics Shandong University Jinan China 《金属学报(英文版)》1993,6(8):112-115
Metal Fe/Pd compositionally modulated films(CMFs) were prepared by vapour depo-sition from two sources onto glass substrate under vacuum.The modulation and crystalstructures of the films were examined by X-ray diffraction.The magnetic properties weredetermined by vibrating sample magnetometer.The Pd layers in the Fe/Pd CMFs areof fcc structure,and the Fe layer structure transits from bcc into amorphous,state withdecreasing thickness of Fe layer.The dependence of specific saturation magnetizationon thickness of Fe layers has also been discussed. 相似文献
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Co/Ti非晶多层膜晶化过程中结构及磁性的变化 总被引:2,自引:0,他引:2
利用双对向靶溅射方法在室温下制备Co/Ti非晶多层膜,并采用原位退火透射电镜和原位热重法,观测了Co/Ti多层膜结构与磁性随温度的变化,结果表明:退火温度ta为400℃时,薄膜开始晶化,Co,Ti颗粒析出并粗化;ta>600℃时,具有铁磁性的Co单质完全消失,全部转化为Co2Ti相.热磁测量在390及520℃附近出现了两个明显的磁性转变峰,与薄膜结构变化对应.适当温度(400—520℃)的退火可获得高饱和磁化强度的Co-Ti颗粒膜. 相似文献
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本文用高速直流溅射装置制备了Fe_(1-x)Pd_x合金,在x=0-0.25的范围内获得了非平衡的单一bcc相。随着x的增加,晶格常数增大,而磁化强度I_s单调地减小。对合金的退火处理结果表明:在570K退火2h,合金仍维持单一的bcc相结构,而在670K退火2h,则发现合金已开始发生相分离。在退火温度T_a<470K时晶格常数和I_s通过退火有所增大,而T_a>470K时晶格常数和I_s则随T_a升高而逐渐减少。 相似文献
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非晶态Fe_(1-x)(Si,B)_x合金的磁矩和磁致伸缩随着Si和B含量的增多而缓慢降低,而Curie温度约在25%(Si+B)含量时呈现出最大值;Si与B的含量对磁各向异性并无明显影响,但表面条纹退磁效应对磁各向异性却有较大的影响。这些实验现象可以借助电子转移和非晶态合金的结构模型得到定性的解释。 相似文献
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GUAN Kehong WANG Jun Northeast University of Technology Shenyang China GUAN Kehong Associate Professor Dept.of Material Science Engineering Northeast Univeristy of Technology Shenyang China 《金属学报(英文版)》1990,3(8):104-106
The magnetic moment and the magnetostriction decrease slightly with the increase of totalSi+B content.A maximum of the Curie temperature appears at about 25 at.-% of Si+B.Themagnetic anisotropy is uninfluential by the content of Si+B,but much influnce by thedemagnetization effect of streak.A qualitative explanation of the experimental phenomenonseems to be noted by the aid of the electron transition and structure model of amorphous al-loys. 相似文献
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TwodrawbacksrestricttheapplicationoftheR2Fe17compoundsaspermanentmagnet:noneofthemexhibitsaneasycaxismagnetocrystallineanisotropyatroomtemperatureandCurietemperatureTcofthemisrelativelylow.Inrecentyears,variousmagneticmaterialsbasedonR2Fe17havebee… 相似文献
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用射频溅射法制备了非晶态CoZr合金薄膜,在0.5Pa的氩气压下,可以得到性能优良的软磁薄膜。研究了非晶态CoZr膜的饱和磁化强度与Zr含量及温度的关系,发现对各种成分的非晶态CoZr膜,在很宽的温度范围内都可满足Bloch T~(3/2)定律。根据刚带模型计算出每个Zr原子向Co的3d能带转移的电荷数约为2.27。 相似文献
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LIU Yihua Shandong University Jinan ChinaYA NG Linqian Huaqiao University Quanzhou Fujian China LIU Yihua Associate Professor Dept.of Physics Shandong University Jinan China 《金属学报(英文版)》1990,3(9):176-180
The amorphous CoZr soft magnetic films with superior properties were prepared byradio-frequency sputtering under pressure of 0.5Pa Ar.The saturation magnetization of theamorphous CoZr films with relation to the Zr content and temperature was investigated.Theamorphous CoZr films composed of different constituents obey the Bloch T~(3/2)-low in a widerange of temperatures.The number of electrons transferred from each Zr atom to 3d energyband of Co calculated by the rigid band model is about 2.27. 相似文献
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通过X射线衍射和磁性测量手段研究了Gd2(Fe0.8Co0.2)17-xGax(0≤X≤8)化合物的结构和磁性。实验结果表明Gd2(Fe0.8Co0.2)17-XCaX化合物均为菱方的Th2Zn17型结构,单胞体积V随Ca含量的增加单调上升,居里温度Tc和饱和磁化强度Ms随Ga含量的增加而单调下降。粉末取向样品的X射线衍射结果表明,随Ga含量的增加,化合物的室温易磁化方向由易面转变为易轴,Gd2(Fe.8Co0.2)17-XCaX化合物的3d亚晶格出现室温单轴各向异性可能与Ca原子的择优占位有关。 相似文献
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Y.M.Hao) Y.Gao) )Department of Physics Tianjin Normal University Tianjin China )Library Tianjin Normal University Tianjin China 《金属学报(英文版)》1999,12(4):474-476
Inpreviouswork〔1〕,wereportedthattherhombohedralorhexagonal2:17phasestructurecanbestabilizedbyreplacingFewithAl.ThesinglephasecompoundsofR2AlFe16xMnx(R=rareearthelement)fromwithMnconcentrationuptox=8forTh2Ni17phaseandx=16forTh2Zn17phase.Inthiswor… 相似文献
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Influence of Sb addition on Martensitic and Magnetic Transformation in β+γ Two-phase Based Co-Ni-Al Shape Memory Alloy 总被引:2,自引:0,他引:2
利用OM,SEM,EDX,XRD,DSC和VSM研究了用Sb替代Al对Co41Ni32Al27合金马氏体相变和磁性的影响.结果表明Co41Ni32Al26Sb1合金仍然生成L10型马氏体,其马氏体相变温度和Curie点与淬火温度成正比关系,淬火温度每升高10K,马氏体相变温度约提高9K,而Curie点约提高7.5K.相同淬火温度下Co41Ni32Al26Sb1合金的马氏体相变温度比Co41Ni32Al27合金约高70K,而Curie点也高出15K.Co41Ni32Al26Sb1在1623K热处理时出现共晶组织,发生部分熔化现象.特别重要的是C041Ni32A12eSbl合金的马氏体相变温度范围大幅度缩小,为20-28K,只有Co41Ni32Al27合金的一半,有利于获得大磁致应变.用平均s+d总电子浓度和平均磁价电子数分别解释了马氏体相变温度和Curie点的变化. 相似文献
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对R2Co17-xSix(R=Ce,Gd和Y)化合物的X射线衍射和磁性测量研究结果表明,Si原子的加入使R2Co17化合物的室温磁晶各向异性由易面转变为易轴,各向异性常数随Si原子浓度的增加而出现极大值、重点讨论了Si原子在Co次晶格四个不同晶位择优占位与Co次晶格磁晶各向异性演化的关系,其中18h晶位对Co次晶格各向异性负贡献起重要作用 相似文献